it's was usually the history where that helped me, I think, but ... okay, area of a trapezoid, for example. not being able to give the area of a trapezoid makes it sound like you memorized the 1/2(b1+b2)h formula and moved on because ... okay I think the derivation should be straightforward if you learned it well: draw either diagonal, now you have two triangles with bases equal to the trapezoid's and altitude equal to its height, and you can add them. and then instead of memorizing a formula before you have an exam on it, you do a problem or two and the derivation has semantic meaning for you instead of "um I remember there are some letters but I don't remember which letters and what order". like if memorize the results you're probably cargo-culting and you can plug numbers in but then you have, like, people you learned that if x+2 = 3 then x=1 and can solve it for arbitrary constants but then are totally stumped by "y+2 = 3, y = ?".
and ... I don't know if this would help you, but if you have thick enough skin for it, try getting some competition. the "wow everyone I care about is getting 18 and I'm scoring an 11 orz" feeling is ... probably individually variable. really helps with setting attainable standards because like a lot of time with classes it's ... hard to tell, and you're always pressured to not fail. but in a competitive setting, especially if you go into it fully expecting not to come out on the other side, you definitely get a good reference point on what is attainable, and even that isn't quite where you'd want to put your goals (... because like, actually setting your goal as being top 5% of humanity, it's basically going to have to come at the expense of something), it puts the goals you are setting into perspective, you know?
competitive environments are great for forcing yourself to learn something thoroughly because in order to distinguish people the problems basically have to be the kind where if you're doing it by rote you're not going to get very far in. and the the reward for success is basically okay, now you have even more you need to learn, you meet more people who are even more better at this than the people who used to seem semi-divine at locals (and now you're one of them), and unless you've been keeping up, just stick around for the show ♥ but the consequence for failure is basically people barely even notice that you're there.
which isn't to say it's not stressful, there's a lot of stress you can make for yourself even without a good reason, but it's the kind of stress where you can legitimately be like okay I can't handle this and take a break, and unless you have a track record of being amazing nobody's going to be severely disappointed in you.
I have no idea where I was going with this but I'm just leaving it here.
... virtual charter school, huh.